The present invention concerns an automatic answering device for a vehicle radio-telephone (hereinafter referred to as "car-phone"). This device answers incoming calls automatically with prerecorded announcements. These recordings can tell the caller to leave a message, advise the caller where the person being called is or when he or she is expected back. They allow a car-phone to be useful 24 hours a day.
The conventional automatic answering device for a car-phone has a circuit as shown in FIG. 1. This conventional circuit comprises a controller 5 for controlling all of the car-phone, a memory 1 for storing program and voice message data to be processed by the controller 5, a display 8 for displaying the results obtained by the controller processing the program and the voice message data, a voice synthesizing circuit 2 for synthesizing the voice message data outputted from the memory 1, a low pass filter 3 for eliminating the high frequency noise produced when synthesizing the voice signal by the voice synthesizing circuit 2 to reproduce the original voice message, a radio transmitting modulator 4 for modulating and transmitting the output of the low pass filter 3, a radio receiving demodulator 7 for demodulating the signal received from a radio-telephone, and a wide band data (WBD) modem 6 for decoding and converting into digital data the dual tone multi-frequency signals with this digital data being recognized by the controller 5.
In this conventional car-phone, when the WBD data is received by the radio receiving demodulator 7, it is demodulated and transferred to the WBD modem 6. The WBD modem 6 decodes and digitalize the received signal which is then transferred to the controller 5. The controller 5 makes the car-phone ring.
The controller 5 processes the data outputted from WBD modem 6 according to the program loaded by the memory 1. The results obtained by the processing are stored into the memory 1, and may be displayed on the display 8 if needed. If the called car-phone user does not answer within a predetermined time, the controller 5 controls the memory 1 to read out the message. If the message signal indicating the absence of the called car-phone user is inputted into the voice signal synthesizing circuit 2, it is synthesized thereby into a voice which is transferred to the low pass filter 3. The voice signal divested of the sampled high frequency noise by the low pass filter 3 is transferred to the radio transmitting modulator 4. The radio transmitting modulator 4 modulates the voice signal so as to transmit it to the caller's car-phone. The voice message transmitted will be as follows:
"Hello, This is the number ***-****. I'm sorry, but he or she is not in. If you would like to speak to him or her, please contact the number ***-****"
then, the caller enters his telephone number and the key *. Thus, the caller's telephone number is stored into the car-phone called. Namely, the caller's telephone number is stored into the memory 1. Thus, the conventional automatic answering device can only transmit the receiver's voice message and store the caller's telephone number, but it cannot store the caller's voice message. Of course, this conventional automatic answering device can store the caller's voice message by using a mechanical recording means. However, the mechanical recording means is adversely affected by mechanical vibrations.